Augmented reality, also referred to as mixed reality, is a new technology developed based on virtual reality. It can increase user's perception of the real world by using information provided by computer system, applying virtual information to the real world, and superimposing computer-generated virtual objects, scenes or system prompts to the real scene, so as to achieve augmentation of reality. The user can not only feel through the virtual reality system the immersive realism experienced in the objective physical world, but also be able to break through the space, time and other objective constraints to have personal experience that would be less possible to happen in the real world. Currently, the technology of augmented reality has been used in navigation, information inquiry and entertainment, etc. For example, by augmented reality, the user can obtain business information or play entertainment animation, and information including the current location, nearby restaurants, tourist attractions and bus stations, etc., can also be displayed to the user. However, the application of augmented reality has been limited so far, for it only allows providing information unidirectionally.